Energy saving is a state policy necessary for a country to establish an energy-saving society. Because of the prominent advantages of energy saving and environmental protection, the amorphous alloy transformers are widely accepted by users, and become a new ideal type of distribution transformers. Currently for the existing amorphous alloy transformers in the market, the three-phase five-leg and three-phase three-leg core structures are commonly adopted. Comparing these two conventional amorphous alloy iron core structures, the three-phase three-leg iron core structure could be deemed as an updated version of the three-phase five-leg core structure, with relatively smaller volume, less weight, and less production time. However, the cross sections of both structures are in a rectangular shape, the design of the transformer is thus restricted by the width of the amorphous alloy materials used, making the design and the manufacture inflexible. In addition, these types of core structure make the transformer with higher weight, higher cost, bigger volume and longer processing time.
Theoretically, the three-phase five-leg and three-phase three-leg core structures are a planar structure, making the magnetic circuit length of each core pillar different. Thus, the balance of three-phase power supply cannot be guaranteed. In addition, the occurrence of seams in the upper and lower iron yokes causes a high energy consuming area around the seams, so that the potential of the amorphous alloy sheets on high magnetic conductibility cannot be fully realized. Furthermore, the air gap formed in the seams increase the corresponding loss. Last but not least, the core and winding with a rectangular structure can reduce the ability of the products to withstand short-circuit.